Yingluck posted a message on her Facebook wall that she was sad that children were killed and she would like to extend her condolence to families of the injured and slain victims.

"I strongly condemn the use of violence in recent days that has caused many deaths both at Trat Province and especially at Rachaprasong today, which is particularly saddening and disturbing since the lives of children were lost," Yingluck said.

She said she has instructed officials concerned to find out the culprits and would punish them no matter which side they belonged to.

Yingluck said her government would not tolerate the act of terrorism for political goal without caring about people's life.

"The government will not tolerate terrorism and has ordered a full investigation by authorities to find the culprits and bring them to justice without exception," her Facebook message said.

She said those with different views should turn to use peaceful measures to express their opinions instead of using violence.

"But the use of violence that leads to deaths are not the civilized way of the living. It is not the way of life of Thais who are naturally considerate and empthatic to fellow citizens, rather than resort to senseless killings. I would like to again call on all sides that it is best to use peaceful means to resolve the political conflict through the democratic process," Yingluck said.